Forecast failure: How flood warnings came too late for southern Albertans

Matt McClure and Trevor Howell, Calgary Herald06.13.2014

Emergency responders rescue stranded High River residents as evening descends on the first day of the flood, June 20, 2013.Lorraine Hjalte
/ Calgary Herald

Trevor Allan, deputy fire chief in High River, was fighting a losing battle as the Highwood River flooded in June. This month, work was underway on a berm were the water came through and flooded the northwest section of the town.Lorraine Hjalte
/ Calgary Herald

Dr. John Pomeroy, director of the Centre for Hydrology at the University of Saskatchewan, checks the instruments on a weather station at Fortress Mountain ski area, part of a network of stations to monitor rain and snow levels in the Rocky Mountains.Gavin Young Gavin Young
/ Calgary Herald

Jacqui Brocklebank, 33, was killed during flooding in High River after rushing to the aid of friend, who was able to escape unharmed.Handout Photo courtesy of Janie Pighin

High River Fire Chief Len Zebedee and his wife Pat, on July 8, 2013 in front of their High River home.They both worked countless hours dealing with the flood.Lorraine Hjalte
/ Calgary Herald

A girl looks out upon flood water in High River on June 20, when the town of High River was hit by massive flooding Thursday. By the time the flood warning was issued in High River at 8:45 a.m. on June 20, most children were at school.Stuart Gradon
/ Calgary Herald

High River, as seen two days after the flood, when water from the Highwood River had already receded substantially.Handout
/ High River RCMP

High River, as seen two days after the flood, when water from the Highwood River had already receded substantially.Handout
/ High River RCMP

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It was shortly after 7 a.m. on June 20 when Trevor Allan finally got his first heads-up that High River was about to be overwhelmed by the worst flood in living memory.

But the deputy fire chief’s warning came from the swollen river, not from the provincial government forecasters whose job it is to alert Albertans to the potential danger from rising waters.

“It came over like a tidal wave,” Allan recalled.

“I saw it broke over the bank, and maybe 15 minutes later it had come across that field and it was already coming up to my knees.”

Allan was part of a team that was working that morning to reinforce flood defences on the town’s northwest outskirts.

An official with the river forecast section in Edmonton had woken him up just four hours earlier with an update.

The caller said that a high stream advisory issued the previous day had just been upgraded to a flood watch because significant rains had fallen in areas upstream during the night and the river might spill over its banks.

“They didn’t give me any indicated flows,” Allan said.

“I recall her saying it had been raining quite heavy in our basin and that’s all I really recall.”

By the time forecasters finally issued a flood warning that fateful morning, many parts of the town would already be under water.

But a Herald analysis shows that nearly eight hours before that public alarm was sounded at 8:45 a.m., rain and river gauge data from stations in the Highwood River’s headwaters showed residents would almost certainly be hit with a disaster worse than the legendary 1995 flood that severely damaged the town.

Click above to see the graphic.

And documents obtained through freedom of information legislation reveal those same provincial officials failed to model in advance for the intense precipitation that some had predicted; they reacted slowly when the heavy rains started to fall; and, they left local officials without timely and accurate flow estimates that might have allowed an orderly evacuation before the town was inundated.

Evan Friesenhan, the forecast section’s manager, has said previously that staff members on duty that night were challenged to adjust their flood predictions promptly because the rain fell more intensely than they expected.

“It was a rapidly changing situation and we were doing our best to make sure … we were getting the information out to the areas that needed it as quickly as possible.

“There’s a lot to learn. We are good at what we do, but there is always a way to improve.”

Three people would perish during the flooding in and around High River.

Among those who died was Jacqui Brocklebank, a 33-year-old woman with cerebral palsy who was knocked into the fast-running waters by a floating trailer.

Brocklebank lost her life while trying to help a friend escape a basement suite overwhelmed by the flooding.

Hundreds of others in High River who began that day without warning of the impending disaster would become stranded and need to be rescued in the front-end loaders of large tractors.

Given the short notice the town received, fire chief Len Zebedee said he is surprised more people didn’t perish.

“I don’t know whether it was good luck, good management or what,” Zebedee said.

“We were fortunate … (the flood didn’t arrive) … in the wee hours of the morning.”

A massive, cyclonic storm had inched ominously toward Alberta’s foothills since the beginning of the week.

On the day before the flood, Environment Canada was predicting that some areas along the eastern slopes would receive up to 150 mm of precipitation over a 48-hour period.

Despite the likelihood that large amounts of warm rain would fall on above-normal snow pack, river forecasters only issued a high stream advisory indicating that low-lying areas of High River might be flooded.

Shortly after that warning was issued Wednesday afternoon, renowned hydrologist John Pomeroy questioned the forecast section’s judgment in an email to a colleague.

Dr. John Pomeroy, Director of the Centre for Hydrology at the University of Saskatchewan,checks the instruments on a weather station. (Gavin Young/Calgary Herald

The first in a chain of messages that was later forwarded to the province and then released in response to the Herald’s FOIP request, it showed at least one expert spotted the impending disaster much sooner than the province’s forecast team.

“(They) just issued a high streamflow advisory, but not a flood watch,” Pomeroy wrote.

"I see a screwup coming."

Other documents reveal the models that flood forecasters developed for the Highwood basin in advance of the rains only assumed a maximum of 110 mm over two days, enough to cause the river to spill its banks at some places in High River and produce minor flooding.

When the skies opened in the mountains west of town that evening, it quickly became clear that the rain was falling much faster than predicted.

Data flowing into the river forecast centre that night showed 50 mm hit the ground in less than three hours at various gauges in the foothills and mountains upstream, an amount that staff had predicted would take 12 hours to fall.

Soon after the rains hit ground that was still frozen in some higher altitude areas, they quickly caused creeks and rivers upstream to flash flood.

Friesenhan has said that readings from river and rain gauges that night were arriving in the forecast section’s computers within an hour of when they were taken.

Staffing schedules show the centre had two forecasters and a technologist working the overnight shift.

It was more personnel than normal, but far fewer staff than would be scheduled to work after the flood hit.

In any event, there were apparently not enough forecasters to spot the worrying numbers coming in from Diebel’s Ranch, a critical river gauging station about 50 km upstream from the town.

Those readings reveal that by 11:45 p.m. flow levels on the Highwood had exceeded the maximum that forecasters had modelled for a minor flood.

Levels at the station continued to spike and by 1 a.m. the river was raging faster and higher than it had during the devastating 1995 flood.

Friesenhan has said that it was during the subsequent two-hour period that staff working — including a forecaster with more than 30 years experience — began to realize what was happening.

“He was seeing the intense rainfalls and we were thinking we have serious concerns,” he said.

In a recent interview, Pomeroy said he is at a loss to understand why forecasters didn’t sound the alarm long and loud when readings at Diebel’s Ranch began to spike.

“I understand the reluctance to issue a false warning,” he said.

“But if you don’t issue one when flooding starts to occur upstream, people can die, evacuations are not orderly and much more property is damaged because there is no chance to protect it or move it out of harm’s way.”

Documents suggest it wasn’t until 2:30 a.m. that forecasters realized that record flow levels had been exceeded and disaster might be imminent.

“Highest measurement ever taken,” the forecaster scrawled on a newly-printed graph that compared actual readings from Diebel’s Ranch with what had been forecast. “Bad data?”

Alberta Environment and Sustainable Resource Development would not provide anyone from the river forecast section to be interviewed for this story.

But in previous answers to Herald questions, section head Chandra Mahabir has suggested staff were distrustful of the readings from Diebel’s Ranch that night.

Asked why her staff had been so slow to react, Mahabir said the spike in levels could have been an indication of a malfunctioning gauge.

However, if the staff on duty had bothered to look at the data from other monitoring stations nearby, they might have realized there was nothing wrong with the measuring equipment.

For example, the graph that night for the Cataract Creek gauge about 20 km upstream showed a similar hockey stick rise in flow levels.

“The forecasters’ reaction is inexplicable,” Pomeroy said.

“An individual gauge can give you a bad reading, but when all your gauges are telling you something’s going on, then you’ve got to believe it and react accordingly.”

Mahabir has said monitoring staff weren’t already in the field or immediately dispatched to check the gauges and verify river readings manually, because it was “too dangerous” to send them out in the middle of the night.

In fact, many of ESRD’s field technologists in southern Alberta were unavailable that night and the next day because they were attending a water rescue course in Kananaskis or were stranded en route when surging rivers washed out roads.

“Techs are the eyes on the ground when flooding happens,” said one department worker the Herald agreed not to identify.

“It was a bad idea to schedule that course at the height of the flood season, and a mistake not to cancel the course when heavy rains were forecast.”

If the forecasters were in disbelief at the dire data they were seeing that night, it may explain why they did not immediately issue a full flood warning when they saw the spike in levels upstream.

Instead, they upgraded the situation in High River to a flood watch at 2:45 a.m. and began trying to reach local officials by phone with the update that the river might come over its banks.

When he didn’t answer either, they called Allan and managed to get him on the phone at around 3 a.m.

While it took a few minutes to get someone on the line, forecasters had little to tell town officials until an hour later when they called Zebedee again.

At 4:18 a.m., they told the fire chief they had updated their model and were now predicting the river would peak late that day at 650 cubic metres per second, roughly the same level as the 2005 floods that damaged low-lying sections of the town.

Pomeroy said that prediction made little sense given the latest reading from the gauge at Diebel’s Ranch.

Before it blew out sometime after 2:30 a.m., the hourly report from the station showed the river was now roaring toward town at 985 cubic metres per second, a rate more than 50 cent higher than the forecasters’ new prediction.

“If it floods upstream, then it’s going to flood downstream and if additional water is pouring in from other creeks along the way it’s likely to get worse as it goes along,” Pomeroy said

“It’s simple gravity, but it seems like there was a mindset that it couldn’t be that bad because that wasn’t what they had modelled.”

When Zebedee got the updated numbers, he immediately organized his firefighters to begin preparing large tubes that would be filled with water and placed in vulnerable areas to protect the town.

High River Fire Chief Len Zebedee and his wife Pat, on July 8, 2013 in front of their High River home.They both worked countless hours dealing with the flood.(Lorraine Hjalte/Calgary Herald

Based on when forecasters had warned of previous floods of this size, he thought the town had half a day to prepare.

As it would turn out, the massive wave of water heading downstream would start overwhelming High River in less than three hours.

Town officials declared a local state of emergency at 7:05 a.m. based on what they were already seeing on the ground.

At his inundated outpost where he was waiting for trucks of gravel that never did arrive, Allan listened as his two-way radio began to squawk.

“There were things happening in other areas of the town,” he said.

“The water is coming in fairly fast at that point, but how do you notify 13,000 people in that short a time span?”

By the time the public flood warning was issued by provincial forecasters at 8:45 a.m., most residents had already gone to work.

Their children were starting the day’s lessons at schools, many of which would soon be surrounded by the rising waters.

Panicked town officials called the provincial forecast section minutes after the province’s warning; they reported that the peak levels that had been predicted to arrive that night had already been exceeded.

Before they got off the phone, there was more shocking news.

The team of forecasters that had come on shift about two hours before had now nearly doubled the estimate of the river’s top flow to 1,270 cubic metres per second.

That translated into another 40 cm rise in the level, enough to overwhelm whatever defences local officials might mount.

“At that point, I know it’s bigger than we’ve ever had before,” said Zebedee, “and I’ve lived here all my life, over 50 years.” As it would turn out, even that forecast was inaccurate. When the Highwood did crest hours later that evening, it reached an estimated peak of more than 1,800 cubic metres per second.

Providing advance warnings to High River was made difficult by the intensity of the rains, Pomeroy said.

The surge in river levels that hit the Diebel’s Ranch gauges arrived in the town just over seven hours later, much less time than during previous events.

Still, during the last major floods in 2005 — when the area received totals of up to 240 mm that fell in less than four days — the town got much more notice.

An internal report shows that during that event, forecasters managed to use precipitation forecasts to issue a flood watch to the town before the rains even started and a full two days prior to the crest in water levels.

A full flood warning was sent out more than 29 hours before peak flows hit the town.

“Alberta had a reputation for first-class forecasting,” said Pomeroy, “but we had a response this time that was reminiscent of what you would expect in a developing country.”

As darkness fell on High River that first night of the flood, first responders in the inundated town were still struggling to rescue stranded residents.

Emergency responders rescue stranded High River residents as evening descends on the first day of the flood, June 20, 2013.(Lorraine Hjalte/Calgary Herald

While the reports of missing persons and deaths were still unconfirmed, provincial politicians were already facing tough questions from reporters about why warnings weren’t issued sooner.

Doug Griffiths, the municipal affairs minister at the time, insisted the province was not caught “flat-footed” by the intense rains and rising waters.

“I have heard every expert I have talked to say there was no way it was going to be that fast, that much of a flood,” Griffiths said.

“The fact that there was so much warning given and our emergency responders were on the ground so quickly … is just a testament to the people … that work with the best information they have.”

Now, the Conservative government appears to believe there may be some room for improvement.

Officials with ESRD issued a tender earlier this month for a consultant to produce a “lessons learned” report on the river forecast section’s handling of the 2013 flood.

Affected communities will be asked to provide “thoughts or concerns” regarding the “communication and information” they were provided before the disaster struck.

Craig Snodgrass, High River’s recently elected mayor, said the town is doing its own forensic review of how the disaster was handled.

But Snodgrass said town officials have already learned one lesson: the next time heavy rains fall, local officials will be searching online themselves for the precipitation readings, seeing how stations on the Highwood River reacts and trusting those numbers.

“If the data looks the way that it looks, and there is this massive peak in flow, you have to pay attention to that and not just say ‘Oh, (the gauge) was broken, I think we are fine,’ ” he said.

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Forecast failure: How flood warnings came too late for southern Albertans

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